Composite cotton and hemp yarn and method for making the same

ABSTRACT

A composite hemp and cotton yarn is formed by blending hemp fibers with cotton fibers which have been regenerated from waste cotton material such as trimmings and cuttings from the apparel manufacturing industry. The fibers are cleaned and blended, then carded to align the fibers into strands. Depending on the size and texture of the desired yarn, the fibers are stretched and drawn into slivers prior to spinning to join the fibers together. The hemp fibers are up to three time longer than the regenerated cotton fibers, so that the hemp fibers overlap and braid onto the regenerated cotton fibers during spinning. The resultant yarn is stronger and more absorbent than yarns made solely out of regenerated cotton fibers or a blend of cotton and acrylic or cotton and polyester fibers.

Textile fabric treatment typically includes bleaching vast amounts ofgreige fabric and then dyeing the fabric to a desired color for use inmanufacturing various fabric articles such as clothing, householdlinens, and canvas. Unfortunately, the effluents produced by thetreatment processes can be harmful to the environment, thus increasingthe costs of manufacture of such fabrics to safeguard the environment.In addition, waste fabric resulting from trimming and cutting the fabricduring the formation of fabric articles must be discarded. The waste istypically dumped into landfills or incinerated, thereby releasingharmful pollutants into the environment and/or atmosphere.

Accordingly, there exists a need to recapture and reuse the waste fabricmaterial, particularly bleached and dyed materials formed of cotton. Thepresent invention relates to the production of yarn from a blend ofregenerated cotton fibers from waste fabric material and of natural hempfibers. No further bleaching or dyeing of the yarn is necessary. Theyarn can be woven or knit into new fabric for production of colorful andfunctional clothing, household linen, canvas and the like.

BRIEF DESCRIPTION OF THE PRIOR ART

It is known in the art to produce a composite yarn formed of vegetableand cotton fibers as disclosed in Haughey U.S. Pat. No. 1,986,970. Amongthe vegetable fibers disclosed in Haughey are hemp. It is also known inthe art to recycle cotton waste material by breaking the material downinto fibers and then blend the recycled fibers with virgin cotton fibersto manufacture yarn having a recycled content as disclosed in theHeifetz U.S. Pat. No. 5,331,801.

While the composite yarns of the prior art are satisfactory, they eachsuffer from certain inherent drawbacks. Neither yarn comprises acomposite of hemp and recycled cotton fibers which can be blended intofine count yarns for manufacturing a variety of fabrics without furthertreatment of the yarn and with minimal damage to the environment. Thepresent invention was developed to provide such a yarn.

SUMMARY OF THE INVENTION

The invention relates to an eco-friendly yarn and a method formanufacturing the yarn. Waste cotton fabric is collected and sorted bycolor and the pieces of fabric of the same color are broken down intocotton fibers referred to as shoddy or fluff by a garnetting process.The cotton shoddy fibers are then blended with natural hemp fibers andspun into pre-dyed yarn. By recycling waste cotton fabric and combiningthe regenerated fibers derived therefrom with hemp fibers, a compositepre-dyed yarn is developed which is environmentally friendly and whichdoes not require further bleaching, dyeing or treatment prior to weavingor knitting of the yarn into articles of clothing, household linens, orother fabric articles.

The finished yarn is between 30 and 45% recycled and regenerated cottonfibers which are generally shorter than the natural hemp fibers. Priorto spinning the fibers into yarn, they are blended and cleaned to removeany impurities from the mixture. Next, the blended fibers are carded toform aligned strands of fibers. The strands may be drawn roved intosmaller finer strands depending on the type of fabric that the yarn isto be used to form. Finally, once the desired strand size has beenobtained, the fibers are spun to form the finished yarn.

BRIEF DESCRIPTION OF THE FIGURES

Other objects and advantages of the invention will become apparent froma study of the following specification when viewed in light of theaccompanying drawing in which,

FIG. 1 is a flow diagram illustrating the method steps used to form theeco-friendly yarn of the present invention.

DETAILED DESCRIPTION

Textile waste in the form of cuttings, trimmings and clippings iscollected from manufacturing facilities around the world before it isdiscarded for deposit in a landfill or incinerated. The waste cottonfabric has previously been bleached and dyed, so additional treatment ordyeing is not required and therefore no additional industrial effluentswhich could add to the further pollution of the environment areproduced.

The waste materials are sorted by color range and cleaned to remove anyforeign material such as paper or metal from labels, buttons, or thelike. Referring to FIG. 1, the sorted waste materials are then subjectedto garnetting 2 which is a process by which materials such as clippingsand trimmings, threads, woven cloth scraps and the like are broken upand returned to a fluffy fibrous condition similar to the original stateof the cotton. This is preferably accomplished by first cutting orchopping the waste materials into smaller pieces of approximately two tosix inches in either direction. The pieces are then fed through a seriesof high speed cylinders having a jagged edged surface to break down thepieces into individual cotton fibers. While any fiber length greaterthan about 0.4 inches is useful, garnetting rarely produces fibershaving a length greater than one and one-eighth inches. Lengths of0.4-0.8 inches are typical, with a length of about 0.5 inches beingaverage and the vast majority being over 0.4 inches.

After garnetting, the regenerated cotton shoddy fibers are lined up in arow or arranged in a circular configuration to be blended by a vacuumhead and separated into large tufts. Long natural hemp fiber on theorder of three inches is added so that the cotton and hemp fibers areblended together 4.

Hemp fiber is produced by processing the stalks of the hemp plant(cannabis sativa L). Hemp is a member of the bast fiber genus which isgrown and cultivated for the long sinuous bast fibers in the stalkswhich include herbaceous plants of dicoeyledons such as flax, hemp,sunn, denaf, jute and ramie. Hemp fiber is naturally organic and do notrequire the use of herbicides or pesticides. One acre of hemp canproduce as much useable fiber as two acres of cotton without the needfor intensive watering or fertilization as is required for traditionalcotton farming. Hemp stalks are cut and left in the field for thirty toforty-five days to ret, a natural process that begins to separate thefibers. Once retted, the stalks are processed by decortication toseparate the fibers into long and short fibers. The cut stalks aresoaked in water and mechanically pulverized to remove and separate thefibers. The fibers are washed to remove the natural glues and thendried.

The tufts of cotton and hemp fiber are air blown into hoppers to cleanthe blended fibers of any remaining dirt or trash 6 prior to delivery tocarding machines 8. The carding machines use air to align the fibersinto a picker lap of parallel fibers. Any remaining dirt or otherparticulates are separated from the picker lap by the air flow. Thepicker lap is in the form of a sheet approximately forty inches wide andone inch thick. The sheet is then processed into a thin mist-like sheetby the carding machines and then formed into loose rope-like strandsreferred to as card-sliver.

A number of card-slivers are brought together and drawn out 10 to form asingle rope like strand known as drawn sliver. The fibers of the drawnsliver are further straightened to improve uniformity. The drawn sliveris further drawn or stretched into smaller strands of fiber by roving12. Finally, the sliver or rope is still further drawn out into a tinystrand of fibers and twisted or spun into yarn 14 using conventionalopen end spinning frames. With the fibers aligned in parallel and spun,they twist together until they cling to each other. The finished yarncounts range between 6s Ne and 28s Ne. The physical difference betweenthe relatively short recycled cotton fibers, typically less than oneinch, and the relatively long hemp fibers, on the order of three inches,results in a very strong yarn as the fibers tend to overlap and braidonto each other. The pre-dyed spun yarn is now suitable for knitting orweaving into colorful and functional apparel and home fashion textiles,without the need for bleaching, dyeing, or other treatment.

Preferably, the amount of cotton fiber in the yarn is less than theamount of hemp fiber. For example, the yarn may comprise 30-45%regenerated cotton fibers, with the balance comprising natural hempfibers. The natural hemp fibers are neutral in color, so the resultingyarn takes on the color of the original cotton waste materials, althoughthe color is muted somewhat by the blending of the hemp fibers.

The benefits of the yarn produced according to the method are many.First, no man-made fibers such as acrylic or polyester are used, whichallows for the production of truly sustainable and eco-friendly yarnsand subsequent woven and knit textile products. Since polyester andacrylic products are petroleum based, there is a net saving in energycost. Because the cotton fibers originate from waste products ofpreviously bleached, dyed or treated fabric, no further treatment,bleach, or dye is used, nor are the waste products deposited intolandfills or incinerated. By blending natural hemp fibers with theregenerated cotton fibers, the fibers may be spun into finer count yarnsto manufacture better quality products than are currently available withconventional regenerated cotton products. In addition, the yarn isstronger and more absorbent than conventional cotton yarn.

While the preferred forms and embodiments of the invention have beenillustrated and described, it will be apparent to those of ordinaryskill in the art that various changes and modifications may be madewithout deviating from the inventive concepts set forth above.

1. A method for making eco-friendly yarn, comprising the steps of (a)sorting waste cotton fabric comprising cuttings and trimmings ofpreviously bleached, dyed and treated cotton fabric by color; (b)garnetting the sorted waste cotton fabric to produce cotton shoddyfibers of the same color therefrom; (c) blending cotton shoddy fibers ofthe same color with natural hemp fibers; and (d) spinning the blendedcotton fibers and hemp fibers to form a yarn having a uniform colorwithout bleaching or dyeing.
 2. (canceled)
 3. A method as defined inclaim 1, wherein the amount of cotton shoddy fibers is less than theamount of natural hemp in the yarn.
 4. A method as defined in claim 3,wherein the yarn comprises 30-45% cotton shoddy fibers.
 5. A method asdefined in claim 2, where in said natural hemp fibers are longer thansaid cotton fibers.
 6. A method as defined in claim 2, and furthercomprising the step of cleaning said blended cotton and hemp fibersprior to said spinning step.
 7. A method as defined in claim 2, whereinsaid fibers are carded to align said fibers into strands prior to saidspinning step.
 8. A method as defined in claim 7, and further comprisingthe step of forming said fibers into smaller strands.
 9. A method asdefined in claim 8, wherein said forming step comprises drawing saidcarded fibers into slivers and subsequently roving said slivers intosmaller strands.
 10. A yarn for making fabric, comprising (a)regenerated cotton fibers formed from waste cotton fabric that haspreviously been bleached, dyed and treated and sorted by color; and (b)natural hemp fibers spun with regenerated cotton fibers of the samecolor, whereby said yarn is colored without bleaching or dyeing.
 11. Ayarn as defined in claim 10, wherein the amount of cotton is less thanthe amount of hemp on the yarn.
 12. A yarn as defined in claim 11,wherein the yarn comprises 30-45% regenerated cotton fibers.
 13. A yarnas defined in claim 10, wherein said hemp fibers are longer than saidcotton fibers.
 14. A yarn as defined in claim 10 and having a fine countof up to 28 Ne.